Prior work on homogeneous catalysts for the metathesis of acetylenes is relatively sparse. The first published report on this subject appears to be that of Mortreux, et al., J. Mol. Catal., 1977, 2, 73. Their work involved use of Mo(CO).sub.6.
There is one report by Edwards and Schrock that a rhenium complex, (Re(C-t-bu)(CH-t-bu)(TMEDA)I.sub.2, will convert several equivalents of 3-heptyne into 3-hexyne and 4-octyne before metathesis ceases. See J. Am. Chem. Soc., 1982, 104, 6806-8.